having trouble setting up my blog and require assistance

Hi, I am trying to set up a blog which seems to be working however there are 2 issues that I can’t resolved.

1. I can’t seem to get the thumbnail to appear on the post (http://www.uych.vic.edu.au/?p=7629) and also the image to appear on the blog page (http://www.uych.vic.edu.au/?page_id=7627)

2. The post has HTML code at the bottom and I can’t locate where that is coming from

Hope you can assist me as I have exhausted all my options and I couldn’t find a blog setup that included comment setup and thumbnails (may have been searching incorrectly however I gave it a good go)

Hope you can help or point me in the right direction